[1764] Follicular Cholecystitis: Reappraisal of Incidence, Definition and Clinicopathologic Associations in an Analysis of 2413 Cholecystectomies

Burcu Saka, Pelin Bagci, Nevra Dursun, Sudeshna Bandyopadhyay, Oscar E Tapia, Juan C Roa, Kee-Taek Jang, Alton B Farris, So Yeon Kong, Ipek Z Kasimoglu, Volkan Adsay. Emory University, Atlanta; WSU, Detroit; UFRO, Temuco, Chile

Background: Follicular cholecystitis (FC) is considered a distinct type of chronic cholecystitis (CC), described initially in patients with salmonella infections. Most studies are limited to case reports or small series. There is no uniform definition, reported incidence ranges from 0.08-8%, and clinicopathologic characteristics are largely undocumented.
Design: 2413 cholecystectomy specimens were analyzed [1348 for non-obstructive pathologies (1138 primary cholecystitis; 210 non-neoplastic polyps);118 for obstructive pathologies (62 distal CBD/pancreatic tumors, 21 autoimmune pancreatitis and 35 primary sclerosing cholangitis), and 947 for in-situ/invasive gallbladder (GB) neoplasms] for prominent lymphoid follicle (LF) formation. FC was defined as 3 LFs per cm of GB tissue.
Results: FC was seen in 44/2413 cholecystectomies (2%). The frequency was similar in non-obstructive, obstructive and GB neoplasm cases (3.4, 2.6, 0.9 %, respectively). When the 34 FC cases in non-neoplastic GBs contrasted with ordinary CC, patients were significantly older (65 vs 49, p<0.0001), but the gallstone frequency (68 vs 70 %), and female:male ratio (3 vs 2.4) were similar. 5/17 had biopsy proven chronic gastritis (2 with activity and 2 with H. pylori). None had lymphoma, parasites or Salmonella. Microscopically, the LFs were the main process; intervening inflammation was minimal; activity (intraepithelial neutrophils) was not common (noted in 8; severe in 1), and likewise for acute and subacute changes (in 3). Average thickness of the wall 4mm (vs 4.8mm in ordinary CC). LFs were predominantly mucosal, with mucosal micropolyps up to 3 mm; however, transmural involvement was seen in 12, and concentrated around vessels and nerves. Average # of LFs identified/case was 22.5 (3-120). Giemsa and immunostain for H.Pylori were negative in 22 analyzed. IgG4-positive plasma cell densities were low (<10/HPF) in 21/24; while 2 had intermediate (10-49) and 1 had high (≥50) levels.
Conclusions: Follicular cholecystitis (FC) constitutes 2% of cholecystectomies. It is seen in significantly older patients, suggesting a deranged immune response, and about a third of the patients reveal a history of biopsy proven gastritis, an issue that warrants further investigation by molecular analysis for organisms. FC does not seem to be associated with any autoimmune conditions (supported by paucity of IgG4 positive plasma cells), malignancies (i.e. follicular lymphoma) or obstructive pathology.
Category: Liver

Wednesday, March 21, 2012 9:30 AM

Poster Session V # 246, Wednesday Morning


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